A. Field of the Invention
The field of the present invention relates generally to devices for bending materials, particularly cold bending of metal materials such as round, rectangular or flat steel stock. More particularly, the present invention relates to such material bending devices that are easily portable and hand operated. Even more particularly the present invention relates to such material benders that are adaptable for mounting to a trailer hitch or like device on the back of a vehicle.
B. Background
Metal materials are utilized as components for many purposes, including products that are configured to have ornamental or decorative aspects, such as metal fences and the like. The metal materials for making the various products generally come in stock form, such as steel tube, bar or sheet stock of various configuration. For instance, stock bars can come in a round, rectangular, square, or other shape of various diameter or thickness. Some of this stock is in a generally flat form. In order to obtain the functional or ornamental configuration, it is often necessary to bend the standard stock materials, also referred to as work objects, into the necessary or desired shape. Both large and small businesses, such as commercial fabrication shops and product-specific shops have a need for cold bending of metal stock.
In general, cold bending is a process of shaping metal into various configurations by bending the stock material without the use of heat. Unlike hot bending, which utilizes heat to “soften” the metal to make it easier to shape, cold bending merely applies a bending force to the metal until the bending force exceeds the material's elastic limit, thereby allowing it to be bent into the desired shape at normal temperatures. Most known cold bending devices utilize various combinations of positioning members to hold the stock material in place, one or more die members to provide the shape(s) around which the stock material is bent and lever-related devices to force the stock material to bend around the die members. Naturally, it is necessary that the machine utilized for bending have components which are stronger than the stock material being bent so that the bending process does not damage the machine instead of bending the stock.
Many material bending machines for cold bending utilize hydraulic and/or electrical components to apply the force necessary to bend the stock into the desired shape. In general, these material bending machines are generally very expensive and require a somewhat significant amount of capital expenditure for the machines, devices associated with operating the machines and the floor space for the machines. Most individuals and small commercial fabrication shops cannot afford the cost for this type of machine. Besides the cost, these machines are generally not configured to be easily moved from one location to another or to be moved to a remote location, such as locations outside the plant, factory or similar fixed location in which they are typically used. In addition, the typical cold bending machine has dies that can be somewhat difficult to change. Another disadvantage of the hydraulically-driven and other non-hand bending machines is that the user of the machine sacrifices his or her ability to “feel” the bending of the stock material. Yet another limitation of hydraulic or other driven material benders is that the person is separate from the material bender and the bending process. It is well known by those skilled in the art of cold bending, that many people like to be able to “feel” the material bending so that they can have more control over the bending process.
Hand bending machines have been in use for many years. One very popular type of hand bending machine is known as the Hossfeld bender. Another hand bending machine for cold bending is the Diacro bender. Although both of these bending machines are very versatile with regard to the types of bending that can be done with the machines, neither machine is configured to be easily transported and used in a field location (i.e., placed in the back of pick-up truck and used at or near where the final product is desired). This is also true of other material benders utilized for cold bending of stock materials. What is needed, therefore, is an improved material bender for cold bending of stock materials that is configured for hand bending, for relatively easy transport and for use in field or remote locations. The preferred material bender should be sized and configured to cold bend different sizes of stock material into various shapes and be easy to change dies in order to obtain those different shapes. Ideally, the material bender should be relatively inexpensive to manufacture, easy to use and adaptable for mounting on or to a vehicle's trailer hitch or like device.